Hi,

PreComfort is similar to a Setback mode.

You will have setpoints associated with Comfort mode, and these in general will also be replicated for PreComfort mode. 

An example where this can be used is fan coil units with PIRs. When the PIR is activated, the unit goes to Comfort mode. When the PIR times out, the unit reverts to a PreComfort mode, with reduced heating setpoints and increased cooling setpoints.

Regards,